Chromium oxide green is an important inorganic product. By virtue of its color fastness and its thermal stability, it is used in particular both as a colored pigment and as a starting material for the production of refractory bricks. Chromium oxide is also used as a raw material in the production of chromium metal and chromium carbide. By virtue of the extreme hardness of the chromium oxide crystallizing in the corundum lattice, it is also used in different formulations as a polish or abrasive.
On an industrial scale, chromium oxide is produced by reduction of alkali chromates with sulfur, sulfur-containing compounds, carbon or carbon-containing compounds or with hydrogen at temperatures around 1000.degree. C. The chromium oxide green, which is dried after the salts have been washed out, is normally marketed in the form of a ground powder.
Handling of the powder during subsequent processing is complicated by dust emission and poor flow behavior which is a disadvantage, above all, in metering and mixing processes.
Accordingly, the industry concerned with subsequent processing requires a chromium oxide green which does not have any of these disadvantages.
Accordingly, the object of the present invention is to provide an improved chromium oxide green which is not attended by and of the described disadvantages.